1. Field of the Invention
The present invention is directed generally to a laser arrangement having a laser with an optical resonator dimensioned so that one or two longitudinal modes of laser oscillation are excited, whereby a polarizer is present in the laser resonator.
2. Description of the Related Art
A laser arrangement is disclosed in Electronics Letters, Feb. 16, 1987, Volume 23, No. 5, pages 206-208. The laser arrangement disclosed therein includes a control in the basis of comparing two modes that lie in the steep regions on the rise or fall of the curve of the gain over frequency so that only a relatively small difference between the two modes is allowed since the control otherwise becomes instable and tends to cut out. This is based on the steepness of the curve of the gain over the frequency.
Some frequency stabilized laser arrangements that relate to monomode lasers are disclosed in the periodical Microwaves, January 1967, pages 51-61. The means for stabilization disclosed in this periodical each share a characteristic wherein a quantity such as resonator length or rotational direction of a circularly polarized light is periodically modified given use of a Zeeman absorption cell as a discriminator. The periodic modification yields a modulation of the laser power, or of the power of the resonator output, that is then converted into a frequency stabilization means. In the known stabilization methods, the laser modulation must occur in low frequency fashion so that a relatively great setting time is required which is in the order of magnitude of a second, for example.